Difference between Amazon S3 and Amazon EBS

Amazon S3 and Amazon EBS are both storage solutions offered by AWS, but they serve different purposes and are designed for different use cases. Here's why you typically wouldn't use S3 as a direct replacement for EBS:

Key Differences Between Amazon S3 and Amazon EBS

1. Storage Type:

   • Amazon S3 (Simple Storage Service): Object storage. S3 is designed to store and retrieve any amount of data from anywhere on the web. Data is stored as objects in buckets, and each object is identified by a unique key.
   • Amazon EBS (Elastic Block Store): Block storage. EBS provides block-level storage volumes that can be attached to EC2 instances. These volumes act like hard drives attached to your instances.

2. Use Case:

   • Amazon S3: Ideal for storing large amounts of unstructured data, such as backups, logs, media files, and static web content. It is optimized for durability, availability, and scalability of data.
   • Amazon EBS: Ideal for use as primary storage for file systems, databases, and applications requiring persistent block storage. EBS is designed for use with EC2 instances, providing low-latency and high-performance storage.

3. Data Access and Performance:

   • Amazon S3: Accessed over HTTP(S) using REST APIs. Not suitable for low-latency, high-throughput transactional applications. S3 is optimized for large data storage and retrieval, not for frequent read/write operations typical of databases or file systems.
   • Amazon EBS: Accessed as block storage directly attached to an EC2 instance. Suitable for low-latency and high-throughput operations. EBS is designed for applications that require frequent and fast read/write operations.

4. Persistence and Availability:

   • Amazon S3: Data is highly durable and available, replicated across multiple facilities within an AWS region. It offers 99.999999999% (11 9's) durability.
   • Amazon EBS: Data is stored within a single Availability Zone but can be snapshot and backed up to S3 for durability. EBS offers high availability within a single AZ and 99.999% reliability for io2 volumes.

5. Data Management:

   • Amazon S3: Object-based storage means you manage data as whole objects. Operations include put, get, delete, and listing objects.
   • Amazon EBS: Block-based storage means you manage data in blocks and can install and manage file systems. Operations include read/write at the block level, which is suitable for databases and operating systems.

6. Cost:

   • Amazon S3: Generally cheaper per GB stored, but costs are incurred for data retrieval (GET requests) and data transfer out.
   • Amazon EBS: Costs are based on provisioned capacity and performance, regardless of usage, and there can be additional charges for IOPS.

Practical Considerations

1. Latency and Throughput:

   • Amazon S3: Higher latency and lower throughput due to its nature as a distributed object store accessed over HTTP. It’s not suitable for applications that require fast and frequent read/write operations.
   • Amazon EBS: Lower latency and higher throughput as it is attached directly to the EC2 instance. Suitable for databases, boot volumes, and applications requiring consistent I/O performance.

2. File Systems and Databases:

   • Amazon S3: Not designed to host file systems or databases that require block storage semantics.
   • Amazon EBS: Specifically designed to be used as block storage for file systems and databases, providing the necessary performance and reliability.

Use Cases

• Use Amazon S3:

  • For storing large objects, backups, and archives.
  • For static website hosting.
  • For serving large files (e.g., videos, images) to users.
  • For log storage and analysis.

• Use Amazon EBS:

  • For running databases like MySQL, PostgreSQL, MongoDB.
  • For boot volumes for EC2 instances.
  • For any application requiring low-latency block storage.